Potential-indicating device.



PATENTED SEPT. 4, 1906.

G. N. EASTMAN. POTENTIAL INDIGATING DEVICE.

APPLICATION FILED MAY5, 1904- w w Jr a a 2 a 4* f v 4/ Z Z o/ Z ya 7 J5 rhuvoma); PETERS PATENT OFFICE.

UNITED STATES GEORGE N. EASTMAN, OF CHICAGO, ILLINOIS, ASSIGNOR TO MINERALLAC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

Specification of Letters Patent.

Patented Sept. 4, 1906.

Application filed May 5. 1904. Serial No. 206,534.

To all whom it may concern;

Be it known that I, GEORGE N. EASTMAN, a citizen of the'United States, residing at Chicago, in the county of Cook and State of Illinois, have invented. a certain new and useful Improvement in Potential Indicating Devices, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to devices for indicating potential, and especially to devices of this kind. for use commercially to indicate potential in power, lighting, and similar plants and systems.

My invention contemplates the use of an electroscopic device to indicate potential in such systems. The means for determining or indicating potential in such systems have heretofore been expensive and complicated, and in the case of broken circuits and detached wires there has not been to my knowledge any practical commercial method of making such an indication to determine whether the wires were dead or alive. By using an electroscopic device for this purpose the condition of a conductor, for example, can be determined by simply presenting the device to it, the result of which willbe that if the wire is alive the device will be actuated and if not there will be no actuation.

The form of electroscopic device I propose to employ and show herein for carrying out my invention comprises a closed and portable receptacle or case, preferably sealed hermetically, and metal leaves inclosed in said case or receptacle, at least one of which is of very light and flexible construction, wh ch permits it to move when electrified. This device can be carried conveniently by any person connected with the power or lighting station when he is out on the outside part of the system, and whenever there is any doubt as to whether or not a wire is alive he can simply use the device by holding it into close relationship with the wire, whereby if the wire is aliv c it will become electrified and so indicate.

In the accompanying drawings, Fi ure 1 is a longitudinalsection of a device em odying my present invention. Figs. 2 and 3 are transverse sections taken on lines 2 2 and 3 3, respectively, inFig. 1; and Fig. 4 is a partial longitudinal section taken on line 4 4 in Fig. 1.

The electroscope shown in the drawings comprises a casing consisting of two separable parts 1 and 2, whereof the part 1 is provided with a shank 3, adapted to fit into a socket end 4 of the part 2. The op osite ends of these two sections or parts 1 aii(l 2 are made so as to be easily grasped by the hand, so as to separate and put the two together, the part 1 being made with a handle 5 at its lower end. This casing is desirably made of wood or similar material. A tube 6, of insulating material, preferably glass, is fitted into the shank 3 and is adapted to fit into the section 2. The tube 6 is hermetically sealed at its outer or upper end by suitable insulating and sealing material 7. The other end of the tube by being fitted into the shank 3 is closed. also, so that the tube is completely closed and sealed. A copper or'other metallic strip 8 is fitted into the outer end of the tube 6 and into the sealing material 7 and is extended down along one side of the tube. A metallic leaf 9 has one of its ends attached to the strip 8, so that its other end or body portion is free to move or swing with reference to the strip 8. In constructing the device the tube 6 is heated, so as to extract all moisture, and then the sealing material 7 is inserted, so that when the tube 6 is hermetically sealed its interior is perfectly dry.

The operation of the device is as follows: The device can be carried around from place to place with the casing 1 in a closed or completed form-that is, with the sheath 2 attached to and partially inclosing the handle portion 1. Whenever it is desired to use the device, the sheath 2 is removed and the outer end of the tube 6 is presented to the electric wire or other article which it is desired to test. If the wire is alive, the leaf 9 will swing or move outwardly away from the strip 9, as shown in dotted lines in Fig. 4. This will indicate that the wire is alive. 7 wire is dead, the leaf 9 will remain stationary. By actual test it has been found that the (le vice will indicate a live wire if its potential is eight hundred volts or more. In other words, the device is sensitive to as low as eight hundred volts potential.

The device is especially useful where fuses have blown out and in similar places where circuits are broken to determine the condition of the difierent sides or ends of the line, and thus by different tests locate the trouble.

The device can be made in other portable If, on the other hand, the

forms embodying the same invention, buthaving different specific constructions. The casing inclosing the tube 6 can be entirely dispensed with, if desired, and this tube made small enough to be readily carried in the pocket.

What I claim as my invention is 1. A device of the class specified, comprising a tube, a closure at one end thereof, a metallic strip held by the closure and extended along the Wall of the tube, and a flexible leaf attached to said metallic strip.

2. A device of the class specified, comprising a tube, a metallic strip secured in position Within said tube and extended along one side thereof, and a flexible metallic leaf secured to said strip.

3. A device of the class specified, compris-v ing a tube, a closure at one end thereof, electrostatic devices carried by said closure, and a sheath inclosing said tube.

4. A device of the class specified, comprising' a tube, electrostatic devices secured Within the tube at one end thereof, a handle at the other end ofithe tube, and a sheath fitted over said tube, and, arranged to slide on and off the end opposite the handle.

5. A device for indicating potential, comprising a hermetically-sealed tube, a metallic strip secured therein, a flexible metallic leaf attached. to said strip, and a casing inclosing said tube.

6. A device for indicating potential, comprising a casing consisting of a handle ortion 1 and a sheath 2, a glass tube 6 fitted into the handle portion 1, a strip 8 fitted into the outer end of the tube 6, and a loose metallic leaf 9 attached to the strip 8, substantially as described.

In Witness whereof I hereunto subscribe my name this 22d day of March, A. D. 1904.

GEORGE N. EASTMAN.

Vitnesses:

A. MILLER BELFIELD, I. 0. LEE. 

